The wiper arms used on motor vehicles usually comprise a fixing part, a joing piece, a wiper rod, and a pressure spring. The fixing part is an essential component part, and forms the means by which the wiper arm is non-rotatably seated on a wiper shaft. The fixing part is typically manufactured from diecast zinc or aluminum. The joint piece is typically punched out of sheet metal and brought to a U-shape. The wiper rod, which is rigidly connected with the joint piece, is articulated at the fixing part and can be swivelled with regard to said joint piece. The pressure spring is usually hung up in the fixing part, on the one hand, and at the joint piece or at the wiper rod, on the other hand. Such a wiper arm is, for example, known from EP 0 301 131 A1. Because of the manufacturing process and the materials used, a fixing part made by diecasting is an expensive component of the wiper arm. This is particularlly true in modern vehicles because the wiper shaft is arranged to an increasing extent in a slot between the windshield and the vehicle body, and therefore, very long fixing parts are used. Because the fixing parts are normally at least partly visible, high quality requirements are made with regard to the surface, which are difficult to satisfy with diecast parts. This leads to a further increase in the price of the fixing parts.
In order to be able to manufacture wiper arms of the requested quality at reduced cost, it has been already suggested, to manufacture the fixing part, too, as a stamped and bent part from sheet metal. A wiper arm with such a fixing part is, for example, known from DE 34 28 795 A1 or DE 39 26 714 A1. The fixing parts of these wiper arms are provided with a back which lies, at least in sections, in a plane vertically to the wiper shaft, and with two side cheeks which are vertically bent away from the back and which point towards the windshield to be cleaned or point away from it. In the two side cheeks bores are provided coaxially arranged towards each other, which, perhaps with the help of a pressed-in bearing bushing accommodate a hinge pin in order to mount the joint piece swivellably at the fixing part. The openings in the side cheeks have to be formed already when the sheet metal is punched out. Only afterwards is the sheet metal bent and drawn to the shape of the fixing part so that an exact coaxial arrangement of the openings is not guaranteed. Furthermore, the known construction techniques require the use of a relatively great amount of material.